With the continuous development of science and technology, various electronic products with display function have entered people's daily life. At present, these electronic products usually adopt a liquid crystal display device (LCD) or an organic light emitting diode display device (OLED).
Organic light emitting diode (OLED) display has become the focus of current research and market due to its advantages of self-luminescence, high contrast, thin thickness, viewing angle light, fast response speed, bendability and wide application temperature range.